package com.deke.gataway.filter;

import com.alibaba.fastjson.JSON;
import com.deke.utils.JwtTool;
import com.deke.vo.Result;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;
import java.nio.charset.StandardCharsets;


/**
 * @author ：Username 刘亦辰（59372312@qq.com）
 * @date ：Created in 2022/12/1 21:41
 * @description：
 * @modified By：
 * @version:
 **/

@Component
public class LoginFilter implements GlobalFilter, Ordered {

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
        //判断请求路径是否为放行。
        String path = request.getPath().toString();
        if("/login".equals(path)){
            return chain.filter(exchange);//放行
        }

        //获取请求头的token值。
        String token = request.getHeaders().getFirst("token");
        if(StringUtils.hasText(token)){
            //校验token是否有效
            if(JwtTool.verifyToken(token)){
                return chain.filter(exchange);//放行
            }
        }

        //3.1设置状态码
        response.setStatusCode(HttpStatus.UNAUTHORIZED);
        //3.2封装返回数据
        Result<String> result = new Result<>(4001,"未登录");
        //3.3作JSON转换
        byte[] bytes = JSON.toJSONString(result).getBytes(StandardCharsets.UTF_8);

        //3.4调用bufferFactory方法,生成DataBuffer对象
        DataBuffer buffer = response.bufferFactory().wrap(bytes);

        //4.调用Mono中的just方法,返回要写给前端的JSON数据
        return response.writeWith(Mono.just(buffer));
    }

    @Override
    public int getOrder() {
        return 0;
    }
}